revision.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "refs.h"
   8 #include "revision.h"
   9
  10 static char *path_name(struct name_path *path, const char *name)
  11 {
  12         struct name_path *p;
  13         char *n, *m;
  14         int nlen = strlen(name);
  15         int len = nlen + 1;
  16
  17         for (p = path; p; p = p->up) {
  18                 if (p->elem_len)
  19                         len += p->elem_len + 1;
  20         }
  21         n = xmalloc(len);
  22         m = n + len - (nlen + 1);
  23         strcpy(m, name);
  24         for (p = path; p; p = p->up) {
  25                 if (p->elem_len) {
  26                         m -= p->elem_len + 1;
  27                         memcpy(m, p->elem, p->elem_len);
  28                         m[p->elem_len] = '/';
  29                 }
  30         }
  31         return n;
  32 }
  33
  34 struct object_list **add_object(struct object *obj,
  35                                        struct object_list **p,
  36                                        struct name_path *path,
  37                                        const char *name)
  38 {
  39         struct object_list *entry = xmalloc(sizeof(*entry));
  40         entry->item = obj;
  41         entry->next = *p;
  42         entry->name = path_name(path, name);
  43         *p = entry;
  44         return &entry->next;
  45 }
  46
  47 static void mark_blob_uninteresting(struct blob *blob)
  48 {
  49         if (blob->object.flags & UNINTERESTING)
  50                 return;
  51         blob->object.flags |= UNINTERESTING;
  52 }
  53
  54 void mark_tree_uninteresting(struct tree *tree)
  55 {
  56         struct tree_desc desc;
  57         struct object *obj = &tree->object;
  58
  59         if (obj->flags & UNINTERESTING)
  60                 return;
  61         obj->flags |= UNINTERESTING;
  62         if (!has_sha1_file(obj->sha1))
  63                 return;
  64         if (parse_tree(tree) < 0)
  65                 die("bad tree %s", sha1_to_hex(obj->sha1));
  66
  67         desc.buf = tree->buffer;
  68         desc.size = tree->size;
  69         while (desc.size) {
  70                 unsigned mode;
  71                 const char *name;
  72                 const unsigned char *sha1;
  73
  74                 sha1 = tree_entry_extract(&desc, &name, &mode);
  75                 update_tree_entry(&desc);
  76
  77                 if (S_ISDIR(mode))
  78                         mark_tree_uninteresting(lookup_tree(sha1));
  79                 else
  80                         mark_blob_uninteresting(lookup_blob(sha1));
  81         }
  82
  83         /*
  84          * We don't care about the tree any more
  85          * after it has been marked uninteresting.
  86          */
  87         free(tree->buffer);
  88         tree->buffer = NULL;
  89 }
  90
  91 void mark_parents_uninteresting(struct commit *commit)
  92 {
  93         struct commit_list *parents = commit->parents;
  94
  95         while (parents) {
  96                 struct commit *commit = parents->item;
  97                 if (!(commit->object.flags & UNINTERESTING)) {
  98                         commit->object.flags |= UNINTERESTING;
  99
 100                         /*
 101                          * Normally we haven't parsed the parent
 102                          * yet, so we won't have a parent of a parent
 103                          * here. However, it may turn out that we've
 104                          * reached this commit some other way (where it
 105                          * wasn't uninteresting), in which case we need
 106                          * to mark its parents recursively too..
 107                          */
 108                         if (commit->parents)
 109                                 mark_parents_uninteresting(commit);
 110                 }
 111
 112                 /*
 113                  * A missing commit is ok iff its parent is marked
 114                  * uninteresting.
 115                  *
 116                  * We just mark such a thing parsed, so that when
 117                  * it is popped next time around, we won't be trying
 118                  * to parse it and get an error.
 119                  */
 120                 if (!has_sha1_file(commit->object.sha1))
 121                         commit->object.parsed = 1;
 122                 parents = parents->next;
 123         }
 124 }
 125
 126 static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 127 {
 128         add_object(obj, &revs->pending_objects, NULL, name);
 129 }
 130
 131 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 132 {
 133         struct object *object;
 134
 135         object = parse_object(sha1);
 136         if (!object)
 137                 die("bad object %s", name);
 138         object->flags |= flags;
 139         return object;
 140 }
 141
 142 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 143 {
 144         unsigned long flags = object->flags;
 145
 146         /*
 147          * Tag object? Look what it points to..
 148          */
 149         while (object->type == tag_type) {
 150                 struct tag *tag = (struct tag *) object;
 151                 if (revs->tag_objects && !(flags & UNINTERESTING))
 152                         add_pending_object(revs, object, tag->tag);
 153                 object = parse_object(tag->tagged->sha1);
 154                 if (!object)
 155                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 156         }
 157
 158         /*
 159          * Commit object? Just return it, we'll do all the complex
 160          * reachability crud.
 161          */
 162         if (object->type == commit_type) {
 163                 struct commit *commit = (struct commit *)object;
 164                 if (parse_commit(commit) < 0)
 165                         die("unable to parse commit %s", name);
 166                 if (flags & UNINTERESTING) {
 167                         commit->object.flags |= UNINTERESTING;
 168                         mark_parents_uninteresting(commit);
 169                         revs->limited = 1;
 170                 }
 171                 return commit;
 172         }
 173
 174         /*
 175          * Tree object? Either mark it uniniteresting, or add it
 176          * to the list of objects to look at later..
 177          */
 178         if (object->type == tree_type) {
 179                 struct tree *tree = (struct tree *)object;
 180                 if (!revs->tree_objects)
 181                         return NULL;
 182                 if (flags & UNINTERESTING) {
 183                         mark_tree_uninteresting(tree);
 184                         return NULL;
 185                 }
 186                 add_pending_object(revs, object, "");
 187                 return NULL;
 188         }
 189
 190         /*
 191          * Blob object? You know the drill by now..
 192          */
 193         if (object->type == blob_type) {
 194                 struct blob *blob = (struct blob *)object;
 195                 if (!revs->blob_objects)
 196                         return NULL;
 197                 if (flags & UNINTERESTING) {
 198                         mark_blob_uninteresting(blob);
 199                         return NULL;
 200                 }
 201                 add_pending_object(revs, object, "");
 202                 return NULL;
 203         }
 204         die("%s is unknown object", name);
 205 }
 206
 207 static int everybody_uninteresting(struct commit_list *orig)
 208 {
 209         struct commit_list *list = orig;
 210         while (list) {
 211                 struct commit *commit = list->item;
 212                 list = list->next;
 213                 if (commit->object.flags & UNINTERESTING)
 214                         continue;
 215                 return 0;
 216         }
 217         return 1;
 218 }
 219
 220 static int tree_difference = REV_TREE_SAME;
 221
 222 static void file_add_remove(struct diff_options *options,
 223                     int addremove, unsigned mode,
 224                     const unsigned char *sha1,
 225                     const char *base, const char *path)
 226 {
 227         int diff = REV_TREE_DIFFERENT;
 228
 229         /*
 230          * Is it an add of a new file? It means that the old tree
 231          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 232          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 233          * (and if it already was "REV_TREE_NEW", we'll keep it
 234          * "REV_TREE_NEW" of course).
 235          */
 236         if (addremove == '+') {
 237                 diff = tree_difference;
 238                 if (diff != REV_TREE_SAME)
 239                         return;
 240                 diff = REV_TREE_NEW;
 241         }
 242         tree_difference = diff;
 243 }
 244
 245 static void file_change(struct diff_options *options,
 246                  unsigned old_mode, unsigned new_mode,
 247                  const unsigned char *old_sha1,
 248                  const unsigned char *new_sha1,
 249                  const char *base, const char *path)
 250 {
 251         tree_difference = REV_TREE_DIFFERENT;
 252 }
 253
 254 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 255 {
 256         if (!t1)
 257                 return REV_TREE_NEW;
 258         if (!t2)
 259                 return REV_TREE_DIFFERENT;
 260         tree_difference = REV_TREE_SAME;
 261         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 262                            &revs->pruning) < 0)
 263                 return REV_TREE_DIFFERENT;
 264         return tree_difference;
 265 }
 266
 267 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 268 {
 269         int retval;
 270         void *tree;
 271         struct tree_desc empty, real;
 272
 273         if (!t1)
 274                 return 0;
 275
 276         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
 277         if (!tree)
 278                 return 0;
 279         real.buf = tree;
 280
 281         empty.buf = "";
 282         empty.size = 0;
 283
 284         tree_difference = 0;
 285         retval = diff_tree(&empty, &real, "", &revs->pruning);
 286         free(tree);
 287
 288         return retval >= 0 && !tree_difference;
 289 }
 290
 291 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 292 {
 293         struct commit_list **pp, *parent;
 294         int tree_changed = 0;
 295
 296         if (!commit->tree)
 297                 return;
 298
 299         if (!commit->parents) {
 300                 if (!rev_same_tree_as_empty(revs, commit->tree))
 301                         commit->object.flags |= TREECHANGE;
 302                 return;
 303         }
 304
 305         pp = &commit->parents;
 306         while ((parent = *pp) != NULL) {
 307                 struct commit *p = parent->item;
 308
 309                 parse_commit(p);
 310                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 311                 case REV_TREE_SAME:
 312                         if (p->object.flags & UNINTERESTING) {
 313                                 /* Even if a merge with an uninteresting
 314                                  * side branch brought the entire change
 315                                  * we are interested in, we do not want
 316                                  * to lose the other branches of this
 317                                  * merge, so we just keep going.
 318                                  */
 319                                 pp = &parent->next;
 320                                 continue;
 321                         }
 322                         parent->next = NULL;
 323                         commit->parents = parent;
 324                         return;
 325
 326                 case REV_TREE_NEW:
 327                         if (revs->remove_empty_trees &&
 328                             rev_same_tree_as_empty(revs, p->tree)) {
 329                                 /* We are adding all the specified
 330                                  * paths from this parent, so the
 331                                  * history beyond this parent is not
 332                                  * interesting.  Remove its parents
 333                                  * (they are grandparents for us).
 334                                  * IOW, we pretend this parent is a
 335                                  * "root" commit.
 336                                  */
 337                                 parse_commit(p);
 338                                 p->parents = NULL;
 339                         }
 340                 /* fallthrough */
 341                 case REV_TREE_DIFFERENT:
 342                         tree_changed = 1;
 343                         pp = &parent->next;
 344                         continue;
 345                 }
 346                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 347         }
 348         if (tree_changed)
 349                 commit->object.flags |= TREECHANGE;
 350 }
 351
 352 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 353 {
 354         struct commit_list *parent = commit->parents;
 355
 356         if (commit->object.flags & ADDED)
 357                 return;
 358         commit->object.flags |= ADDED;
 359
 360         /*
 361          * If the commit is uninteresting, don't try to
 362          * prune parents - we want the maximal uninteresting
 363          * set.
 364          *
 365          * Normally we haven't parsed the parent
 366          * yet, so we won't have a parent of a parent
 367          * here. However, it may turn out that we've
 368          * reached this commit some other way (where it
 369          * wasn't uninteresting), in which case we need
 370          * to mark its parents recursively too..
 371          */
 372         if (commit->object.flags & UNINTERESTING) {
 373                 while (parent) {
 374                         struct commit *p = parent->item;
 375                         parent = parent->next;
 376                         parse_commit(p);
 377                         p->object.flags |= UNINTERESTING;
 378                         if (p->parents)
 379                                 mark_parents_uninteresting(p);
 380                         if (p->object.flags & SEEN)
 381                                 continue;
 382                         p->object.flags |= SEEN;
 383                         insert_by_date(p, list);
 384                 }
 385                 return;
 386         }
 387
 388         /*
 389          * Ok, the commit wasn't uninteresting. Try to
 390          * simplify the commit history and find the parent
 391          * that has no differences in the path set if one exists.
 392          */
 393         if (revs->prune_fn)
 394                 revs->prune_fn(revs, commit);
 395
 396         if (revs->no_walk)
 397                 return;
 398
 399         parent = commit->parents;
 400         while (parent) {
 401                 struct commit *p = parent->item;
 402
 403                 parent = parent->next;
 404
 405                 parse_commit(p);
 406                 if (p->object.flags & SEEN)
 407                         continue;
 408                 p->object.flags |= SEEN;
 409                 insert_by_date(p, list);
 410         }
 411 }
 412
 413 static void limit_list(struct rev_info *revs)
 414 {
 415         struct commit_list *list = revs->commits;
 416         struct commit_list *newlist = NULL;
 417         struct commit_list **p = &newlist;
 418
 419         while (list) {
 420                 struct commit_list *entry = list;
 421                 struct commit *commit = list->item;
 422                 struct object *obj = &commit->object;
 423
 424                 list = list->next;
 425                 free(entry);
 426
 427                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 428                         obj->flags |= UNINTERESTING;
 429                 if (revs->unpacked && has_sha1_pack(obj->sha1))
 430                         obj->flags |= UNINTERESTING;
 431                 add_parents_to_list(revs, commit, &list);
 432                 if (obj->flags & UNINTERESTING) {
 433                         mark_parents_uninteresting(commit);
 434                         if (everybody_uninteresting(list))
 435                                 break;
 436                         continue;
 437                 }
 438                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 439                         continue;
 440                 p = &commit_list_insert(commit, p)->next;
 441         }
 442         if (revs->boundary) {
 443                 /* mark the ones that are on the result list first */
 444                 for (list = newlist; list; list = list->next) {
 445                         struct commit *commit = list->item;
 446                         commit->object.flags |= TMP_MARK;
 447                 }
 448                 for (list = newlist; list; list = list->next) {
 449                         struct commit *commit = list->item;
 450                         struct object *obj = &commit->object;
 451                         struct commit_list *parent;
 452                         if (obj->flags & UNINTERESTING)
 453                                 continue;
 454                         for (parent = commit->parents;
 455                              parent;
 456                              parent = parent->next) {
 457                                 struct commit *pcommit = parent->item;
 458                                 if (!(pcommit->object.flags & UNINTERESTING))
 459                                         continue;
 460                                 pcommit->object.flags |= BOUNDARY;
 461                                 if (pcommit->object.flags & TMP_MARK)
 462                                         continue;
 463                                 pcommit->object.flags |= TMP_MARK;
 464                                 p = &commit_list_insert(pcommit, p)->next;
 465                         }
 466                 }
 467                 for (list = newlist; list; list = list->next) {
 468                         struct commit *commit = list->item;
 469                         commit->object.flags &= ~TMP_MARK;
 470                 }
 471         }
 472         revs->commits = newlist;
 473 }
 474
 475 static int all_flags;
 476 static struct rev_info *all_revs;
 477
 478 static int handle_one_ref(const char *path, const unsigned char *sha1)
 479 {
 480         struct object *object = get_reference(all_revs, path, sha1, all_flags);
 481         add_pending_object(all_revs, object, "");
 482         return 0;
 483 }
 484
 485 static void handle_all(struct rev_info *revs, unsigned flags)
 486 {
 487         all_revs = revs;
 488         all_flags = flags;
 489         for_each_ref(handle_one_ref);
 490 }
 491
 492 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 493 {
 494         unsigned char sha1[20];
 495         struct object *it;
 496         struct commit *commit;
 497         struct commit_list *parents;
 498
 499         if (*arg == '^') {
 500                 flags ^= UNINTERESTING;
 501                 arg++;
 502         }
 503         if (get_sha1(arg, sha1))
 504                 return 0;
 505         while (1) {
 506                 it = get_reference(revs, arg, sha1, 0);
 507                 if (strcmp(it->type, tag_type))
 508                         break;
 509                 memcpy(sha1, ((struct tag*)it)->tagged->sha1, 20);
 510         }
 511         if (strcmp(it->type, commit_type))
 512                 return 0;
 513         commit = (struct commit *)it;
 514         for (parents = commit->parents; parents; parents = parents->next) {
 515                 it = &parents->item->object;
 516                 it->flags |= flags;
 517                 add_pending_object(revs, it, arg);
 518         }
 519         return 1;
 520 }
 521
 522 void init_revisions(struct rev_info *revs)
 523 {
 524         memset(revs, 0, sizeof(*revs));
 525
 526         revs->abbrev = DEFAULT_ABBREV;
 527         revs->ignore_merges = 1;
 528         revs->pruning.recursive = 1;
 529         revs->pruning.add_remove = file_add_remove;
 530         revs->pruning.change = file_change;
 531         revs->lifo = 1;
 532         revs->dense = 1;
 533         revs->prefix = setup_git_directory();
 534         revs->max_age = -1;
 535         revs->min_age = -1;
 536         revs->max_count = -1;
 537
 538         revs->prune_fn = NULL;
 539         revs->prune_data = NULL;
 540
 541         revs->topo_setter = topo_sort_default_setter;
 542         revs->topo_getter = topo_sort_default_getter;
 543
 544         revs->commit_format = CMIT_FMT_DEFAULT;
 545
 546         diff_setup(&revs->diffopt);
 547 }
 548
 549 /*
 550  * Parse revision information, filling in the "rev_info" structure,
 551  * and removing the used arguments from the argument list.
 552  *
 553  * Returns the number of arguments left that weren't recognized
 554  * (which are also moved to the head of the argument list)
 555  */
 556 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 557 {
 558         int i, flags, seen_dashdash;
 559         const char **unrecognized = argv + 1;
 560         int left = 1;
 561
 562         /* First, search for "--" */
 563         seen_dashdash = 0;
 564         for (i = 1; i < argc; i++) {
 565                 const char *arg = argv[i];
 566                 if (strcmp(arg, "--"))
 567                         continue;
 568                 argv[i] = NULL;
 569                 argc = i;
 570                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 571                 seen_dashdash = 1;
 572                 break;
 573         }
 574
 575         flags = 0;
 576         for (i = 1; i < argc; i++) {
 577                 struct object *object;
 578                 const char *arg = argv[i];
 579                 unsigned char sha1[20];
 580                 char *dotdot;
 581                 int local_flags;
 582
 583                 if (*arg == '-') {
 584                         int opts;
 585                         if (!strncmp(arg, "--max-count=", 12)) {
 586                                 revs->max_count = atoi(arg + 12);
 587                                 continue;
 588                         }
 589                         /* accept -<digit>, like traditional "head" */
 590                         if ((*arg == '-') && isdigit(arg[1])) {
 591                                 revs->max_count = atoi(arg + 1);
 592                                 continue;
 593                         }
 594                         if (!strcmp(arg, "-n")) {
 595                                 if (argc <= i + 1)
 596                                         die("-n requires an argument");
 597                                 revs->max_count = atoi(argv[++i]);
 598                                 continue;
 599                         }
 600                         if (!strncmp(arg,"-n",2)) {
 601                                 revs->max_count = atoi(arg + 2);
 602                                 continue;
 603                         }
 604                         if (!strncmp(arg, "--max-age=", 10)) {
 605                                 revs->max_age = atoi(arg + 10);
 606                                 continue;
 607                         }
 608                         if (!strncmp(arg, "--since=", 8)) {
 609                                 revs->max_age = approxidate(arg + 8);
 610                                 continue;
 611                         }
 612                         if (!strncmp(arg, "--after=", 8)) {
 613                                 revs->max_age = approxidate(arg + 8);
 614                                 continue;
 615                         }
 616                         if (!strncmp(arg, "--min-age=", 10)) {
 617                                 revs->min_age = atoi(arg + 10);
 618                                 continue;
 619                         }
 620                         if (!strncmp(arg, "--before=", 9)) {
 621                                 revs->min_age = approxidate(arg + 9);
 622                                 continue;
 623                         }
 624                         if (!strncmp(arg, "--until=", 8)) {
 625                                 revs->min_age = approxidate(arg + 8);
 626                                 continue;
 627                         }
 628                         if (!strcmp(arg, "--all")) {
 629                                 handle_all(revs, flags);
 630                                 continue;
 631                         }
 632                         if (!strcmp(arg, "--not")) {
 633                                 flags ^= UNINTERESTING;
 634                                 continue;
 635                         }
 636                         if (!strcmp(arg, "--default")) {
 637                                 if (++i >= argc)
 638                                         die("bad --default argument");
 639                                 def = argv[i];
 640                                 continue;
 641                         }
 642                         if (!strcmp(arg, "--topo-order")) {
 643                                 revs->topo_order = 1;
 644                                 continue;
 645                         }
 646                         if (!strcmp(arg, "--date-order")) {
 647                                 revs->lifo = 0;
 648                                 revs->topo_order = 1;
 649                                 continue;
 650                         }
 651                         if (!strcmp(arg, "--parents")) {
 652                                 revs->parents = 1;
 653                                 continue;
 654                         }
 655                         if (!strcmp(arg, "--dense")) {
 656                                 revs->dense = 1;
 657                                 continue;
 658                         }
 659                         if (!strcmp(arg, "--sparse")) {
 660                                 revs->dense = 0;
 661                                 continue;
 662                         }
 663                         if (!strcmp(arg, "--remove-empty")) {
 664                                 revs->remove_empty_trees = 1;
 665                                 continue;
 666                         }
 667                         if (!strcmp(arg, "--no-merges")) {
 668                                 revs->no_merges = 1;
 669                                 continue;
 670                         }
 671                         if (!strcmp(arg, "--boundary")) {
 672                                 revs->boundary = 1;
 673                                 continue;
 674                         }
 675                         if (!strcmp(arg, "--objects")) {
 676                                 revs->tag_objects = 1;
 677                                 revs->tree_objects = 1;
 678                                 revs->blob_objects = 1;
 679                                 continue;
 680                         }
 681                         if (!strcmp(arg, "--objects-edge")) {
 682                                 revs->tag_objects = 1;
 683                                 revs->tree_objects = 1;
 684                                 revs->blob_objects = 1;
 685                                 revs->edge_hint = 1;
 686                                 continue;
 687                         }
 688                         if (!strcmp(arg, "--unpacked")) {
 689                                 revs->unpacked = 1;
 690                                 continue;
 691                         }
 692                         if (!strcmp(arg, "-r")) {
 693                                 revs->diff = 1;
 694                                 revs->diffopt.recursive = 1;
 695                                 continue;
 696                         }
 697                         if (!strcmp(arg, "-t")) {
 698                                 revs->diff = 1;
 699                                 revs->diffopt.recursive = 1;
 700                                 revs->diffopt.tree_in_recursive = 1;
 701                                 continue;
 702                         }
 703                         if (!strcmp(arg, "-m")) {
 704                                 revs->ignore_merges = 0;
 705                                 continue;
 706                         }
 707                         if (!strcmp(arg, "-c")) {
 708                                 revs->diff = 1;
 709                                 revs->dense_combined_merges = 0;
 710                                 revs->combine_merges = 1;
 711                                 continue;
 712                         }
 713                         if (!strcmp(arg, "--cc")) {
 714                                 revs->diff = 1;
 715                                 revs->dense_combined_merges = 1;
 716                                 revs->combine_merges = 1;
 717                                 continue;
 718                         }
 719                         if (!strcmp(arg, "-v")) {
 720                                 revs->verbose_header = 1;
 721                                 continue;
 722                         }
 723                         if (!strncmp(arg, "--pretty", 8)) {
 724                                 revs->verbose_header = 1;
 725                                 revs->commit_format = get_commit_format(arg+8);
 726                                 continue;
 727                         }
 728                         if (!strcmp(arg, "--root")) {
 729                                 revs->show_root_diff = 1;
 730                                 continue;
 731                         }
 732                         if (!strcmp(arg, "--no-commit-id")) {
 733                                 revs->no_commit_id = 1;
 734                                 continue;
 735                         }
 736                         if (!strcmp(arg, "--always")) {
 737                                 revs->always_show_header = 1;
 738                                 continue;
 739                         }
 740                         if (!strcmp(arg, "--no-abbrev")) {
 741                                 revs->abbrev = 0;
 742                                 continue;
 743                         }
 744                         if (!strcmp(arg, "--abbrev")) {
 745                                 revs->abbrev = DEFAULT_ABBREV;
 746                                 continue;
 747                         }
 748                         if (!strncmp(arg, "--abbrev=", 9)) {
 749                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
 750                                 if (revs->abbrev < MINIMUM_ABBREV)
 751                                         revs->abbrev = MINIMUM_ABBREV;
 752                                 else if (revs->abbrev > 40)
 753                                         revs->abbrev = 40;
 754                                 continue;
 755                         }
 756                         if (!strcmp(arg, "--abbrev-commit")) {
 757                                 revs->abbrev_commit = 1;
 758                                 continue;
 759                         }
 760                         if (!strcmp(arg, "--full-diff")) {
 761                                 revs->diff = 1;
 762                                 revs->full_diff = 1;
 763                                 continue;
 764                         }
 765                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 766                         if (opts > 0) {
 767                                 revs->diff = 1;
 768                                 i += opts - 1;
 769                                 continue;
 770                         }
 771                         *unrecognized++ = arg;
 772                         left++;
 773                         continue;
 774                 }
 775                 dotdot = strstr(arg, "..");
 776                 if (dotdot) {
 777                         unsigned char from_sha1[20];
 778                         const char *next = dotdot + 2;
 779                         const char *this = arg;
 780                         *dotdot = 0;
 781                         if (!*next)
 782                                 next = "HEAD";
 783                         if (dotdot == arg)
 784                                 this = "HEAD";
 785                         if (!get_sha1(this, from_sha1) &&
 786                             !get_sha1(next, sha1)) {
 787                                 struct object *exclude;
 788                                 struct object *include;
 789
 790                                 exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
 791                                 include = get_reference(revs, next, sha1, flags);
 792                                 if (!exclude || !include)
 793                                         die("Invalid revision range %s..%s", arg, next);
 794
 795                                 if (!seen_dashdash) {
 796                                         *dotdot = '.';
 797                                         verify_non_filename(revs->prefix, arg);
 798                                 }
 799                                 add_pending_object(revs, exclude, this);
 800                                 add_pending_object(revs, include, next);
 801                                 continue;
 802                         }
 803                         *dotdot = '.';
 804                 }
 805                 dotdot = strstr(arg, "^@");
 806                 if (dotdot && !dotdot[2]) {
 807                         *dotdot = 0;
 808                         if (add_parents_only(revs, arg, flags))
 809                                 continue;
 810                         *dotdot = '^';
 811                 }
 812                 local_flags = 0;
 813                 if (*arg == '^') {
 814                         local_flags = UNINTERESTING;
 815                         arg++;
 816                 }
 817                 if (get_sha1(arg, sha1)) {
 818                         int j;
 819
 820                         if (seen_dashdash || local_flags)
 821                                 die("bad revision '%s'", arg);
 822
 823                         /* If we didn't have a "--":
 824                          * (1) all filenames must exist;
 825                          * (2) all rev-args must not be interpretable
 826                          *     as a valid filename.
 827                          * but the latter we have checked in the main loop.
 828                          */
 829                         for (j = i; j < argc; j++)
 830                                 verify_filename(revs->prefix, argv[j]);
 831
 832                         revs->prune_data = get_pathspec(revs->prefix, argv + i);
 833                         break;
 834                 }
 835                 if (!seen_dashdash)
 836                         verify_non_filename(revs->prefix, arg);
 837                 object = get_reference(revs, arg, sha1, flags ^ local_flags);
 838                 add_pending_object(revs, object, arg);
 839         }
 840         if (def && !revs->pending_objects) {
 841                 unsigned char sha1[20];
 842                 struct object *object;
 843                 if (get_sha1(def, sha1))
 844                         die("bad default revision '%s'", def);
 845                 object = get_reference(revs, def, sha1, 0);
 846                 add_pending_object(revs, object, def);
 847         }
 848
 849         if (revs->topo_order || revs->unpacked)
 850                 revs->limited = 1;
 851
 852         if (revs->prune_data) {
 853                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 854                 revs->prune_fn = try_to_simplify_commit;
 855                 if (!revs->full_diff)
 856                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 857         }
 858         if (revs->combine_merges) {
 859                 revs->ignore_merges = 0;
 860                 if (revs->dense_combined_merges &&
 861                     (revs->diffopt.output_format != DIFF_FORMAT_DIFFSTAT))
 862                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 863         }
 864         revs->diffopt.abbrev = revs->abbrev;
 865         diff_setup_done(&revs->diffopt);
 866
 867         return left;
 868 }
 869
 870 void prepare_revision_walk(struct rev_info *revs)
 871 {
 872         struct object_list *list;
 873
 874         list = revs->pending_objects;
 875         revs->pending_objects = NULL;
 876         while (list) {
 877                 struct commit *commit = handle_commit(revs, list->item, list->name);
 878                 if (commit) {
 879                         if (!(commit->object.flags & SEEN)) {
 880                                 commit->object.flags |= SEEN;
 881                                 insert_by_date(commit, &revs->commits);
 882                         }
 883                 }
 884                 list = list->next;
 885         }
 886
 887         if (revs->no_walk)
 888                 return;
 889         if (revs->limited)
 890                 limit_list(revs);
 891         if (revs->topo_order)
 892                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
 893                                              revs->topo_setter,
 894                                              revs->topo_getter);
 895 }
 896
 897 static int rewrite_one(struct rev_info *revs, struct commit **pp)
 898 {
 899         for (;;) {
 900                 struct commit *p = *pp;
 901                 if (!revs->limited)
 902                         add_parents_to_list(revs, p, &revs->commits);
 903                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
 904                         return 0;
 905                 if (!p->parents)
 906                         return -1;
 907                 *pp = p->parents->item;
 908         }
 909 }
 910
 911 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
 912 {
 913         struct commit_list **pp = &commit->parents;
 914         while (*pp) {
 915                 struct commit_list *parent = *pp;
 916                 if (rewrite_one(revs, &parent->item) < 0) {
 917                         *pp = parent->next;
 918                         continue;
 919                 }
 920                 pp = &parent->next;
 921         }
 922 }
 923
 924 static void mark_boundary_to_show(struct commit *commit)
 925 {
 926         struct commit_list *p = commit->parents;
 927         while (p) {
 928                 commit = p->item;
 929                 p = p->next;
 930                 if (commit->object.flags & BOUNDARY)
 931                         commit->object.flags |= BOUNDARY_SHOW;
 932         }
 933 }
 934
 935 struct commit *get_revision(struct rev_info *revs)
 936 {
 937         struct commit_list *list = revs->commits;
 938
 939         if (!list)
 940                 return NULL;
 941
 942         /* Check the max_count ... */
 943         switch (revs->max_count) {
 944         case -1:
 945                 break;
 946         case 0:
 947                 return NULL;
 948         default:
 949                 revs->max_count--;
 950         }
 951
 952         do {
 953                 struct commit *commit = revs->commits->item;
 954
 955                 revs->commits = revs->commits->next;
 956
 957                 /*
 958                  * If we haven't done the list limiting, we need to look at
 959                  * the parents here. We also need to do the date-based limiting
 960                  * that we'd otherwise have done in limit_list().
 961                  */
 962                 if (!revs->limited) {
 963                         if ((revs->unpacked &&
 964                              has_sha1_pack(commit->object.sha1)) ||
 965                             (revs->max_age != -1 &&
 966                              (commit->date < revs->max_age)))
 967                                 continue;
 968                         add_parents_to_list(revs, commit, &revs->commits);
 969                 }
 970                 if (commit->object.flags & SHOWN)
 971                         continue;
 972
 973                 /* We want to show boundary commits only when their
 974                  * children are shown.  When path-limiter is in effect,
 975                  * rewrite_parents() drops some commits from getting shown,
 976                  * and there is no point showing boundary parents that
 977                  * are not shown.  After rewrite_parents() rewrites the
 978                  * parents of a commit that is shown, we mark the boundary
 979                  * parents with BOUNDARY_SHOW.
 980                  */
 981                 if (commit->object.flags & BOUNDARY_SHOW) {
 982                         commit->object.flags |= SHOWN;
 983                         return commit;
 984                 }
 985                 if (commit->object.flags & UNINTERESTING)
 986                         continue;
 987                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 988                         continue;
 989                 if (revs->no_merges &&
 990                     commit->parents && commit->parents->next)
 991                         continue;
 992                 if (revs->prune_fn && revs->dense) {
 993                         if (!(commit->object.flags & TREECHANGE))
 994                                 continue;
 995                         if (revs->parents)
 996                                 rewrite_parents(revs, commit);
 997                 }
 998                 if (revs->boundary)
 999                         mark_boundary_to_show(commit);
1000                 commit->object.flags |= SHOWN;
1001                 return commit;
1002         } while (revs->commits);
1003         return NULL;
1004 }